


The Same Battle (mortal instruments x supernatural)

by CoolC17



Category: Mortal Instruments Series - Cassandra Clare, Supernatural, The Mortal Instruments, The Mortal Instruments (Movies)
Genre: Crossover, Gen
Language: English
Status: In-Progress
Published: 2016-06-03
Updated: 2016-10-26
Packaged: 2018-07-11 23:01:47
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 4
Words: 2,534
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7074172
Author URL: https://archiveofourown.org/users/CoolC17/pseuds/CoolC17
Summary: <blockquote class="userstuff">
              <p>Jace, Clary, Alec, and Isabelle head to a warehouse on reports of demon attacks only to find that their work had been done for them....maybe mundanes aren't so useless after all. </p>
<p>Mortal Instruments Supernatural Crossover fic. Clace, Sizzy, and Malec. Takes place after COHF and at the beginning of season 9, when they were searching for Abbadon.</p>
            </blockquote>





	1. Angel Blade (Clary POV)

I slide the dagger into the sheath on my belt, and look at myself in the mirror.

I'm wearing my black gear, with my weapons belt strapped on holding three daggers, my stele, and lastly Heosphoros, my weapon of choice that shows my family heritage. My orange-red hair is pulled back into a high ponytail, and I have a determined look on my face.

I hear a knock on my door, and soon hear Jace's voice.

"Ready Clary?" He asks through the door.

"Yep." I answer simply, and open the door. My boyfriend stares down at me, though not as far down as before. I've grown a few inches since we escaped Edom five months ago.

Jace is wearing the same simple black gear as me, I like how he looks in it, the dark shade makes his golden eyes look even brighter.

"Well let's go then." Jace says, and starts to lead me to the front of the institute, where Isabelle and Alec are waiting.

"This should just be a simple clean out, there shouldn't be more than ten demons there, should be easy." Isabelle says, zipping up her leather jacket.

"It's kind of annoying, being given the easiest jobs, I mean, does the Clave seriously still think of us as just children? I mean by the Angel, we stopped the war." Jace remarks in an annoyed tone.

"Yeah but I mean what are we gonna do about it? It's not like we can really complain, like you said in the eyes of the Clave we are still legally children, well, except for Alec" Isabelle replies in a slightly angry voice.

Before the conversation can continue any further, Simon exits the front doors of the institute. He's wearing faded jeans and I light blue t-shirt that says "The Cake is a Lie". He looks out of place in a group of heavily armed teenagers. Unfortunately Simon can't go hunting with us just yet, seeing as he's still a mundane, but he's been studying and training to become a shadowhunter by drinking from the mortal cup.

"Going hunting?" He asks casually.

"Yeah, we should be back soon." I reply.

"Be careful."

"Of course."

"Alright we should get going." Alec says.

I reach into my belt and pull out my stele, then draw the portal rune on the ground. Seconds later a shimmering blue portal appears, I look at the photograph of the warehouse where the supposed demon attacks have taken place. I keep the picture in my head as I step through the portal, soon followed by the others.

 

I look around, slightly disoriented from the portal travel but soon see a gigantic building. It seems to have aged over the years, as the red paint is faded and the metal doors are very rusty. Then Jace leads the way into the warehouse.

I pull out Heosphoros and cautiously step through the door, followed by Alec and Isabelle. Luckily I had the foresight to draw soundless and swiftness runes on both my ankles, as I suspect the others did as well. We didn't bother putting glamours on since this particular warehouse happens to be abandoned.

We stop dead in our tracks when we see dead bodies scattered around, all stabbed in the heart.

"Victims do you think?" Alec asks.

"They must be, what else could they be?" Isabelle whispers back.

We follow the hallway until we hear a voice loudly say "Now we could do this the easy way, or the hard way. Personally I'd prefer the latter." 

We all freeze and look around for the source of the voice. We soon find it.

In the center of the room there's a women tied to a chair in the center of a pentagram. Standing beside the chair looking at the girl are two men who look to be in their early 30's. The one on the right of her is fairly tall and is wearing a blood splattered large brown leather coat with normal jeans and boots. The one on the left is even taller and has brown almost shoulder length hair, with a large brown coat, also bloodstained and seems to be wearing a flannel underneath.

The one on the right punches the girl whom I'm beginning to assume is a demon. "Until you talk I can do this all day." He says arrogantly, and punches her again, harder. 

"I'll ask you again, where are the rest of you?" The other one asks forcefully.

"There's no more of us! I swear!" The demon screams.

"Bullshit."

"If there were more of us, which there aren't, don't you think backup would have come by now?" The demon screeches.

"We don't have time for this."

The one on the right sighs, and swiftly stabs the demon with an odd looking blade. The demon dies almost instantly. 

I examine the men closer, the don't seem to be shadowhunters, but somehow they have something that can kill a demon, not to mention that they even know that demons exist. Since I've been a shadowhunter for a while now I can sense if someone's a demon or a downworlder, and these two don't seem to be either, but it wouldn't make sense for them to be mundanes.

"Do you really think that could have been all of them?" The taller one asks.

"I mean it did have a point, if there are more, why didn't they come and help their buddy over here?" He nudges the body with his boot.

"Whatever, man. Let's just get back to the motel."

Jace stands up and I know it's time to approach them. We stride toward them and I try to look confident but I'm really nervous, whatever these guys are it's not normal. The shorter one notices us first and is obviously startled by our amount of weapons.

"Woah woah woah" He says anxiously while holding his hands up. "We don't want any trouble. You guys hunters?" Does he mean shadowhunters?

"Yeah we are but you're not so what the hell are you? You seem like mundanes but what kind of mundane can kill a demon?" Jace says, seeming unfazed by the situation unfolding.

"Look man, we're just hunters doing our job, okay? We're not looking for a fight." The taller one says, trying to calm the situation down.

"If you're a shadowhunter then where are your runes?" Alec asks sharply.

"A what? I have no idea what you're talking about dude" The shorter one says, but he seems to be telling the truth. 

"If you're not a shadowhunter then how did you kill a demon?" Alec asks.

"With this" The shorter one holds out a simple looking silver blade, it slightly resembles a seraph blade.

"It's an angel blade" the tall one supplies. "Look, we can talk this out. I'm Sam Winchester and that's my brother Dean. We came here investigating a case of demonic possession, so we came here and killed the demons, we're hunters."

"Alright." Alec says hesitantly. "I'm Alec, that's my sister Isabelle,  Jace, and Clary." We all keep defensive stances but with less tension than before, we outnumber them and they don't seem to want to escalate to violence.

"How about we talk over dinner at Taki's, we can both explain our sides of what's going on, okay?" Alec says, trying to resolve the conflict.

"Fine." Dean, who now has a name, says. "But I wouldn't try anything if I were you."


	2. Taki's (Jace POV)

"The usual?" Kaelie asks.

"Yeah." I answer, I probably sound stressed.

"And for you two?" She asks, directing the question at Sam and Dean.

"I'll have a short stack of pancakes and coffee." Dean replies, and I catch him winking at her.

"Just coffee, thanks." Sam says.

"Alright then"

I turn to the two brothers whom we just met.

"So what are you?" I ask forcefully, and I feel the others glare at me.

"We told you, we're hunters. And you guys obviously are too, what kind of normal person just strolls around with an arsenal of weapons on them and just casually walks into a demon infested warehouse." Dean says impatiently.

"Look, just, start from the beginning, what exactly is a hunter?" Alec asks them.

The two men look at each other before Sam hesitantly answers. "Hunters are just people that kill things that are paranormal and proposing a threat toward others."

"And that's why you guys were at the warehouse?" 

"Yes." they say in unison.

"And what kind of mundane would want to hunt monsters?"

"Well most hunters are seeking revenge on a monster that hurt them, or got sucked into this life one way or another." Sam answers gloomily.

"And why are you two hunters?" Clary asks softly.

There's a few seconds of silence before Dean answers. "When we were young our mother was killed by a demon, then our father raised us to hunt." He says, not going into too much detail.

We all fall silent for a moment.

"And who are you?" Dean demands. "Some kind of punk teenage gang who thinks they know a thing or two about the paranormal?"

We all exchange looks before Alec sighs and tells them the truth.

"We're Shadowhunters."

"What, is that your gang name?" Dean asks arrogantly.

"That is a species of half angel warriors created to defend human kind from demons." Alec says, losing his temper.

"Then why have we never heard of you?" Sam asks, seeming concerned.

"Well, I don't know, it might have something to do with the fact that you're mundanes." Isabelle answers instead of Alec.

"Listen here, we've met demons, angels, killed both, been to heaven and hell, but not once have we heard a single word about some freaky species of human-angel hybrids." Dean spouts.

He must be lying, no way what he just said is true. I raise my eyebrows challengingly at him.

"Look dude, maybe we should call Cas and have him clear things up, maybe they're telling the truth." Sam says, probably trying to be reasonable.

"Who the hell is Cas?" I demand.

"Castiel. He's an angel." Dean answers impatiently.

They must be insane.

"An angel?" I challenge, unfazed.

"Yeah, he's a buddy of ours. And let me just say he has never mentioned a word of anything called a shadowhunter." Dean answers.

"And how would you guys, know an angel?" Alec asks the obvious question.

"Well.. Let's see. We met him when the apocalypse started, did you Shadowhunters know anything about that? If you're supposed to be defending man kind from demons, you're not doing a very good job of it." Dean snaps.

Yep. Definitely insane.

"Look, if you guys don't believe us, why don't you just meet him? And we can get this all cleared up. Surely if there was a hybrid species of angels and humans, Cas would know about it." Sam says.

We look at each other and shrug.

"Fine."


	3. Castiel (Dean POV)

Me and Sam lead the so called 'Shadowhunters' behind the diner we had been eating at, so hopefully nobody notices some guy in a trench coat appearing out of nowhere.

"And how exactly are you planning to call an angel." Isabelle asks, more arrogantly then she should in her position.

"We pray." I answer simply, not actually knowing the specific mechanics of how prayer works. "Now quiet." The group falls silent.

I press my hands together in a praying position. "Hey Cas, me and Sam are in New York behind some diner called Taki's. Come quick, you've got some explaining to do." He really needs to just get a phone. 

I open my eyes and stare at the teenagers surrounding me with expectant expressions on their faces. Only seconds later Castiel appears in front of us, with his usual expressionless face.

I stare at 'Shadowhunters' and find them staring in surprise and awe, however not nearly as much as a normal person would.

Even Castiel looks curiously at them, until he walks up to the red-headed one, and slowly looks at her hand. He takes a step back and actually has a small smile on his face. 

"Ah, I see. You're Raziel's children." He says in a monotone voice. Raziel seems like an angel's name, and they did say they were half Angel.

'Jace', I think seems to regain his composure the fastest, and blurts out a reply.

"What are you?" He asks.

"I'm an angel. It makes sense that you wouldn't be able to recognize one in it's vessel, as the only angel you've seen was in it's true form."

"Wait, I thought that anyone who saw an angel in it's true form had their eyes burned out, you know, like Pamela." Sam asks in his confusion.

"Well Raziel's children are only able to witness an angel in it's true form because they're half angel." Castiel replies casually, like it's a well known fact.

"Wait." I gesture to the shadowhunters "It's possible to be half angel?! Why haven't we ever ran into one?" I ask him.

"The nephilum were created by the Angel Raziel to protect humans or 'mundanes' as they call them, from demons." Cas explains.

"Well what a great job they've been doing, seeing as they were nowhere to be seen during the apocalypse." I growl angrily. They're supposed to protect humans from demons, but completely left them on their own to sort out the end of the world?

"What do you mean apocalypse?" Alec asks, looking concerned. "I'm pretty sure if the world was ending, we would know." 

"You were purposefully kept in the dark during the apocalypse by the other Angels, you were not equipped to battle lucifer, especially seeing as you were fighting your own war at the time." Castiel says.

"So while we were fighting Sebastian...." Clary starts, but doesn't finish her reply.

"The apocalypse was happening." Castiel finishes.

The group shares looks with one another, before Alec speaks up.

"And why should we believe you?"

"I know Raziel, he's a good warrior, and I know all of your history, without actually being one of you, nor a downworlder or demon. Is that not proof enough?" Castiel says in a finalizing tone.

Alec seems to have a thoughtful expression on his face before finalizing his answer.

"Alright."


	4. Update

Hey guys. It's been a VERY long time since I've posted a chapter here, I know. I didn't expect this fanfic to get any attention whatsoever. I'd like to update this, but, after going over the first few chapters I've written I've realized a couple things.

1\. I'm rather unsatisfied with my writing in these chapters. If I do decide to continue writing this, I'll rewrite the current chapters before writing new ones.  
2\. I have absolutely no idea where to go with the story. My writers block with this fanfic is generally what discouraged me from continuing it in the first place. But a lot of people have read this, so PLEASE let me know where you think this story should go. I really need actual ideas, and without them I can't keep writing.

Thank you so much for reading this, and I'm sorry for my huge gap in updates. So like I mentioned, leave a comment with any ideas or comments you have.

**Author's Note:**

> Please leave any opinions in the comments.


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